Abstract:Schools of yellowfin tuna associate with dolphins in the eastern tropical Pacific (ETP) Ocean. U.S. fishermen began to exploit this resource in the late 1950s by encircling the dolphins with large purse seine nets to capture the yellowfin tuna swimming beneath them. Despite efforts to release the entrapped dolphins (which were of no value to U.S. fishermen) while landing the tuna, dolphins became entangled in the nets and drowned. By the early 1970s, as many as 300,000 or more dolphins may have been drowned each year by U.S. tuna seiners in the ETP. From its inception in 1972, one of the goals of the Marine Mammal Protection Act (MMPA) was to reduce the incidental mortality of dolphins in the ETP tuna fishery. Regulations promulgated under MMPA authority set standards for tuna seining and motivated technological improvements that reduced dolphin mortalities in this fishery -- by 1977, annual dolphin mortality by U.S. tuna seiners had declined to about 25,450 animals. Despite the extensive mortalities, no ETP dolphin population has been listed as endangered or threatened under the U.S. Endangered Species Act. However, two ETP dolphin stocks were listed as depleted under the MMPA. The ETP purse seine fishery was dominated by U.S. vessels through the 1960s and into the 1970s. By the 1980s, the U.S. fleet was declining, and more foreign vessels were entering the fishery. With this shift, total dolphin mortality began to increase again until more than 100,000 dolphins were killed by foreign tuna purse seine vessels in 1986. In April 1990, the three largest U.S. tuna processors announced that they would no longer purchase tuna caught in association with dolphins. This action caused many U.S. tuna seiners to relocate to the western Pacific. Congress responded by enacting the Dolphin Protection Consumer Information Act to set standards for labeling tuna as ¨dolphin-safe,¨ and the International Dolphin Conservation Act of 1992 to prohibit the sale, purchase, transport, or shipment in the United States of any tuna that was not dolphin-safe. In response, foreign nations strengthened their programs for protecting dolphins during tuna seining through the non-binding International Dolphin Conservation Program developed by the Inter-American Tropical Tuna Commission. However, foreign nations barred from the U.S. tuna market became increasingly vocal that the United States should recognize their success in reducing dolphin mortalities by reopening the U.S. market to their tuna. A Declaration of Panama was signed by 12 nations including the United States in October 1995, agreeing to modify U.S. law in exchange for binding commitments for further progress in dolphin protection. Four bills, introduced in the 104th Congress to implement the Declaration of Panama, differed on how U.S. law should be changed, particularly whether the definition of ¨dolphin-safe¨ tuna should be modified. This issue remained unresolved in the 104th Congress, and was taken up by the 105th Congress where compromise language was passed in H.R. 408. This measure was signed by President Clinton as P.L. 105-42 on August 15, 1997. [read report]